Hernias of the : Anatomy in the Male

Bob Caruthers. CST. PhD

The surgical repair of an inguinal , although one of the in this discussion. The anterolateral group consists of two mus- most common of surgical procedures, presents a special chal- cle groups whose bodies are near the midline and whose fibers lenge: anatomy remains one of the more difficult topics are oriented vertically in the standing human: the rectus abdo- to master for both the entry-level student and the first assistant. minis and the pyramidalis. The muscle bodies of the other This article reviews the relevant anatomy of the male groin. three groups are more lateral, have significantly larger aponeu- roses, and have obliquely oriented fibers. These three groups MAJOR FASClAL AND UGAMENTAL STRUCTURES contribute the major portion of the fascia1 and ligamental The abdominal wall contains muscle groups representing two structures in the groin area.',!.' broad areas: anterolateral and posterior (see Figure 1).The At the level of the , the layers of the abdomi- posterior muscles, the quadratus lumborum, do not concern us nal wall include , (Camper's and

(cut edge)

Internal abdominal (cut and turned down)

Lacunar (Gimbernatk)

Inguinal (Poupart k) 11ganenr (medial origin)

Cremaster muscle [lateral origin)

Falx inguinalis [conjoined tendon) Cremaster muscle and

Reflected External spermatic fascia (cut)

Figun, 1-Dissection of rhe anterior ahdominal wall. (posterior layerl , Inferior epigastric vessels Deep inguinal ring , (cut away)

'.,."" -- Rectus abdomlnls muscle \ Antenor-supenor 111acspme \ -. ,lliopsoas muscle

Hesselbach'sl triangle

inguinalis (conjoined) , Tesricular vessels and genital branch of genitofmoral

Scarpa's fascia), external oblique fascia, from the upper six ribs course downward inguinal (Poupart's) ligament. This liga- cremasteric muscle fibers, spermatic obliquely and anteriorly to become the ment marks, in the groin, the separation cord structures, the transversus abdo- external oblique aponeurosis. The between the abdominal wall and the minis aponeurosis, the transversalis fas- aponeurotic fibers from each side inter- lower limb. that occur immedi- cia, preperitoneal tissues, and peri- lace with fibers from the opposite side ately above this ligament are considered toneum.'.'.' in the . Fibers of the external to be in the inguinal area, while hernias abdominal oblique fuse with fibers from existing below the ligament are called

EXTERNAL ABDOMINAL OBUQUE the underlying internal abdominal femoral hernias (see Figures 2 and 3). MUSCLE oblique to form the sheath of the rectus The more medial of the rolled-under The external abdominal oblique muscle abdominis muscle.'.:,'.' fibers of the inguinal ligament flatten is the most superficial, thickest, and into a horizontal shelf. These fibers largest of the anterolateral muscle INGUINAL LIGAMENT attach to the os , and this continu- groups. The muscle body is found later- In the groin area, a continuation of the ation of the inguinal ligament is called ally, having a strong, flat aponeurosis aponeurosis of the external abdominal the lacunar (Gimbernat's) ligament. occurring anteriorly. The external oblique stretches from the pubic tuber- The , which courses abdominal oblique muscle arises from cle to the anterior-superior iliac spine. through the inguinal canal, rests on the the lower outside border of the lower This extension is a rolled-under, inferior until it turns to exit eight ribs. Fibers from the bottom two margin of the aponeurosis of the exter- through the superficial inguinal ring. ribs insert in the , while fibers nal abdominal oblique and is called the Fibers that continue laterally along the

26 Fchruarv IYQB Thm Srr#loal T~ohnolo~lst anterior border of the superior ramus of In the upper , the intemal ic fascia and serves as the middle one of the pubis contribute to the pectineal abdominal oblique aponuerosis splits at the three covering layers oi the cord (Cooper's) ligament.'.'.' the linea sernilunaris, having an anterior and testis (see Figure 4).'.' and posterior sheath. In the lower quar- ter of the abdomen, the aponeurosis does INTERNAL ABDOMINAL OBLIQUE TRANSVERSUS ABDOMlNlS MUSCLE not split, but masses to the midline, MUSCLE The intemal abdominal oblique mus- anterior to the . The transversus abdominis muscle is the cle-as the middle one of the three flat The lower fibers arch over the spermatic innermost of the flat muscles of the abdominal muscles-is a thin, muscular cord and insert in the superior border of abdomen, having an extensive and var- sheet arising from the posterior layer of the pubis. These fibers join with similar ied origin in the cartilages of the six the thoracolumbar fascia, the anterior fibers from the transversalis tnuscle to lower ribs, the thoracolumbar fascia, the two-thirds of the iliac crest, the lateral form the falx inguinalis.'.',' iliac crest, and the inguinal ligament. two-thirds of the inguinal ligament, and The internal surface of the muscle is the iliacus fascia. Posterior fibers ascend lined by the tranversalis fascia.'.:.' CRENlASLlR MUSCLE AND vertically to the inferior borders of the FASCIA lower 3 or 4 ribs, while the other fibers The cremaster muscle originates from TRANSVERSAUS FASCIA spread fan-like in a forward and medial the inferior margin of the intemal The endoabdominal fascia forms a con- fashion. The ultimate insertion of these abdominal oblique muscle and forms tinuous lining of the . fibers is the linea alba and the pubic part of the coverings of the cord and When this fascia lies deep to the trans- bone. testis: It underlies the external spermat- versus abdominis muscle. it is labeled

Inferior epigastric vessels /covered by transversalis fascia) Linea alba

External abdominal oblique muscle Transversalis fascia (site of / direct )

Aponeurosis of external Falx inguinalis (conjohed tendon) abdominal oblique muscle

Trarlsveaus abdominis muscle Crenlaster muscle (medial origin)

Cremaster muscle (lateral origin) lntercrural fibers

Inguina! iPoupart's)ligament

~xternalspermatic fascia on Lacunar IGimbernark) ligament spermatic cord exiting

Superficial inguinal ring Pectineal (Cooperk) ligament

Reflected inguinal ligament / I ' Superficial inguinal ring Lateral crus

Figure 3-Dissecrton of the ~nguinalregion (anrerior vtew). "transversalis fascia." When the canal is the deep inguinal ring found lacunar ; the posterior wall- endoabdominal fascia is incact, no her- above the midpoint of the inguinal liga- sometimes called the "floorn-is formed nia exists; therefore, all hernias in the ment. The deep inguinal ring is not by the transversalis fascia and transver- groin represent a defect in the transver- truly "ring-like," but a finger-like diver- sus abdominis muscle. salis fascia. This fascia is attached to the ticulum of the transversalis fascia. The In the male, the contents of the iliac crest and descends upon the iliac canal is directed lateral to medial, deep inguinal canal include the ; fascia, serving as the superior fascia of to superficial, and cephalad to caudad, deferential and vein; testicular the pelvic diaphragm. The internal exiting at the superficial inguinal ring artery; lymphatics; autonomic ; spermatic fascia is the principle out- occurring above and lateral to the pubic the ilioinguinal and genital por- pouching of the transversalis fascia; its tubercle. tion of the ; and the mouth is the deep inguinal ring.".' Whereas the superficial boundary of cremaster artery, which is a branch of the canal is formed by the external the inferior epigastric artery.'".'.' INGUINAL CANAL oblique aponeurosis, the most cephalad The inguinal canal is approximately wall is formed by the intemal oblique INFERIOR EPIGASTRIC VESSELS 4-cm long and obliquely oriented; it lies and tranversus muscles, along with The external iliac supply blood 2 cm to 4 cm above and parallel to the aponeurotic fibers from each. The infe- to the legs, and the intemal iliac arteries inguinal ligament. Entrance to the rior wall is formed by the inguinal and supply the and perineum. The

Ductus (vasl deferens covered by Erternal iliac vessels covered by peritoneum Internal abdominal oblique muscle \ Ductus (vas) deferens External abdominal oblique muscle

Inferior epigastric vessels Transversus abdominis muscle

Cremasteric vessels Transversalis fascia

Medial umbilical ligament (obliterated )

Rectus abdominis mcacle Internal spermatic fascia

Superficial inguinal ring

'Spermatic cord

External spermatic fascia \ Femoral vessels enveloping spermatic cord

Cremaster muscle and / \ Inguinal (Poupartk) ligament fascia on sperrnaric cord . . / \:::-. I Figure 4-Spemur~c cord and ~ngulnalcanal

28 Febru~r\I"*S Tho Surgical Toohnoiogist External abdominal

External abdominal Rectus shearh (anterior layer)

Anterior-super~oriliac spine Superficial epigastric vessels

Intercrural fibers Inguinal (Poupartk) ligament

ring

Figure &Femoral and inguinal regions (subcutaneous fascia has been removed). external iliac artery passes under the INGUlNAL HERNIAS The techniques of hernia repair are inguinal ligament at a point midway Several schemes are used to describe her- beyond the scope of this review, but the between the anterior-superior iliac spine nias: One of the more traditional distinc- certified surgical technologist will recog- and the symphysis pubis: At that cross- tions made when referring to inguinal nize that the various methods of repair ing point, it becomes the . hernias is that between direct and indirect tend to make use of different ligaments The external iliac artery follows the hernias. The indirect inguinal hernia is to reconstruct an intact and sufficiently medial border of the psoas muscle, giv- characterized by a herniation of abdomi- strong transversalis fascia1 plane.12.'" ing off several branches. The inferior nal contents into an unobliterated vagi- epigastric artery branches from the nal process within the coverings of the REFERENCES external iliac artery just above the spermatic cord that begins at the deep 1. Woodburne RT, Burke1 WE. inguinal ligament and has its origin at inguinal ring. The structures traverse the Essentials of Human Anatomy. 8th ed. the medial border of the deep inguinal inguinal canal to emerge at the superfi- New York, NY: Oxford University ring. The spermatic cord passes behind cial inguinal ring, and the contents may Press, 1988. and lateral to the epigastric artery and descend into the (see Figure 5). 2. Wantz GE. Open Repuir of Hernias of vein. The direct inguinal hernia, which the Abdominal Wall.Scientific By using three points-the inferior occurs one-third as frequently as the American CD-ROM. Scientific epigastric artery and vein, the symphysis indirect hernia, develops secondarily to a American Inc, 1997. ~ubis,and the rectus abdominis muscle weakness in the superficial inguinal ring 3. Netter E A Guide to the interactive as it reaches the midline of the and the abdominal wall lateral to the Atlas of Human Anatomy. Summit, abdomen-one can create an imaginary falx inguinalis. The inferior epigastric NJ: Ciba-Geigy Corporation, 1995. triangle called "Hesselbach's triangle," artery lies lateral to the mass; that is to 4. Sabiston DC. Textbook of Surgery: which is used to determine whether a say, the mass occurs in Hesselbach's tri- The Biological Basis of Modem Surgical hernia is considered direct or indi- angle. The covering layers of this type of Practice. Philadelphia, Pa: W.B. rect. I.'.' hernia are those of the abdominal wall. Saunders Co, 1997. A